Novel artificial sensor mimics human sense of touch

Seoul, Nov 8 : Korean researchers have developed an artificial tactile sensor that mimics the ability of the human skin to detect surface information such as shapes, patterns and structures.

The device may be one step closer to making electronic devices and robots that can perceive sensations such as roughness and smoothness.

"Mimicking the human senses is one of the most popular areas of engineering, but the sense of touch is notoriously difficult to replicate," said lead author Kwonsik Shin, engineer at Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea.

In the study, published in the journal IEEE/ASME Transactions on Mechatronics, the team developed a sensor from piezoelectric materials -- highly sensitive materials that can generate electrical power as a response to applied stress.

These materials have similar properties to skin.

Compared to existing artificial sensors, the new sensor can detect signals through both touch and sliding, mimicking the two ways humans sense surface -- by poking or running our fingers over it.

Further, the new sensor also consists of an array of multiple receptors, meaning that sliding speed can be calculated using the time interval between two receptor signals and the distance between them.

Most robot fingers use a single receptor, requiring an external speedometer.

The researchers tested their sensor by pressing stamps shaped like a square, triangle or dome against the sensor surface.

They also added soft material to the sensor to see if it could measure depth, thus sensing in three dimensions.

The sensor produced different voltages depending on the shape of the stamp.

The results show that the sensor has high spatial resolution and can represent the surface characteristics of certain objects, such as the width and pitch, with high accuracy.

In the future, the sensor could be incorporated into electronic devices, such as robots or smart phones, to improve their ability to detect surface textures, the researchers said.